Select which floor's database you want to examine. Once you have selected the floor, you may examine the offices that have been marked for that floor, then click on "Change Floor" to select another floor.
If you examine this map, then add users, then examine this map again, and you don't see the users, it is probably because Netscape has cached the user database, and you aren't seeing the most recent copy. To fix this, just hold down the Shift key and press the Reload button; this will reload the applet and the database.